This is a revised application for the Community Collaboration Core (CCC). Community-research collaborations involving academia, community-based organizations (CBOs), clinical care settings, and health departments can ensure high-quality HIV prevention science and address health disparities among diverse underserved groups. These "research-practice" collaborations make it possible to target interventions to the needs of well-defined groups; tailor approaches to address culturally specific beliefs about gender, sexuality, and health; and promote healthy lifestyles through enduring community ties. However, many questions about undertaking and evaluating collaborations remain unanswered and require systematic scientific inquiry. The CCC will integrate scientific and community responses to the HIV epidemic by providing technical assistance to foster and support research partnerships and by developing theoretical models to advance scientific understanding of the collaborative process. Building on the HIV Center's 15 year history of promoting "community-informed research" and "research-informed services in the community," the aims of the CCC are (1) to initiate and sustain successful partnerships to conduct HIV prevention and treatment research and program activities related to sexuality, gender, and mental health that are of mutual interest and benefit to communities; and (2) to develop and disseminate theoretical models and methods that will advance the science of the collaborative process in the field of HIV prevention and treatment and may then be applied to other areas of health behavior research. Risk-determinant studies and development of effective interventions in diverse populations are facilitated through community-academic partnerships and are central to the mission of the HIV Center. Drawing on existing relationships and expertise at the Center and in the community, we have assembled an interdisciplinary group of behavioral scientists, representatives from key CBOs, primary care clinics, and New York State and City governmental planning and policy bodies to support and strengthen community-research collaborations and advance the scientific basis for understanding partnership. To achieve these objectives, the Core will engage in the following key activities: community outreach; triage and formation of consultation teams; ongoing consultations, technical assistance, and case conference reviews; and model building in the study of partnerships and the collaborative process.